Manually operable tool for installing tubular rivets



Jan. 15, 1952 s. L. GOOKIN 2,582,248

MANUALLY OPERABLE TOOL FOR INSTALLING TUBULAR RIVETS Filed March 29, 1949 2 SHEETS-SHEET 1 Inven for 45911265562" L. Goo/(in Byz's 1 orney Jan. 15, 1952 s. L. GOOKIN 2,582,248

MANUALLY OPERABLE TOOL FOR INSTALLING TUBULAR RIVETS Filed mmn 29, 1949 2 SHEETS-SHEET 2 [n pen far 52 SyZueszerl. Gookin Patented Jan. 15, 1952 MANUALLY OPERABLE TOOL FOR INSTALLING TUBULAR RIVETS Sylvester L. Gookin, Quincy, Mass assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application March 29, 1949, Serial No. 84,016

6 Claims.

This invention relates to a tool for installing tubular rivets. More particularly, the invention pertains to a manually operable riveting tool of the type which acts on a mandril telescopically related to the rivet to insert and upset the latter from one side of the structure being riveted. While thus intended primarily for blind riveting, it will be understood that this invention may well have other applications.

In the art of blind riveting the installation of a tubular rivet that has been preassembled with a less ductile mandril is known to have certain advantages. With such assemblages, sometimes referred to as pop rivets, the practice is to insert the rivet barrel in an aperture of the structure to be pivoted and, while holding a flanged head-of the rivet against the structure, to retract the mandril so that its head upsets the rivet barrel and thereby causes the upset portions to clench the structure tightly. A further characteristic peculiar to pop-riveting is that the mandril stem, which is ordinarily inexpensive and expendable, is further tensioned after upsetting its rivet and, at a frangible part of the stem,

the mandril is strained beyond its elastic limit and broken. The rivet joint so obtained is rigid,

will withstand rather high shearing stress, and, if the mandril head be securely lodged within the rivet as is the normal case, the joint may be watertight. 1 I

Tools have hitherto been provided for installing two-part rivets as just described. A difliculty commonly met with in using many of these tools effectively, however, has been that where the mandril gripping and pulling power has been adequate, their weight and complexity have been such as severely to detract from their maneuverability. On the other hand, other tools reduced in weight and intended for manual operation have afiorded maneuverability but lacked the requisite capacity easily to break and dispose of the mandril stem.

In view of the above circumstances the chief object of the present invention is to provide an improved hand tool for installing rivets of the aforesaid character, which tool shall be simple in construction and operation, easily manipulated and yet capable of setting such rivets and then breaking and ejecting their respective mandril stems in work strokes requiring the expenditure of a minimum of effort.

With this object in view, one feature of the invention is the provision of an operating hand lever for retracting the main body of the tool from its anvil, and novel mandril gripping mechanism constituting a self-contained unit within tenings outside the tool body and also the lever is effective to enhance the gripping power of the mechanism as the tension increases.

A further feature of the invention resides in the provision of means for automatically releasing and ejecting the broken mandril stem from the tool after the end of an operating stroke, said means comprising mechanism for monentarily restraining a mandril gripping jaw in inoperable position at the end of said stroke so as to enable an energized element forcibly to expel the broken mandril stem from the tool.

The above and other features of the invention will now be described in more detail with reference to its embodiment in a tool shown in the attached drawings, in which Fig. 1 is an elevational View of the riveting tool exemplifying this invention, extremities of the operating lever (shown in initial position) and main body being broken away;

Fig. 2 is an elevational view of most of the tool shown in Fig. l, but turned about its longitudinal axis;

Fig. 3 is a partly sectional and partly elevational view of the tool on an enlarged scale and as seen in Fig. 2 but having its elements in their initial positions prior to riveting a structure;

Fig. 4 is a view similar to Fig. 3 and illustrating the same tool with its parts in a subsequent operating stage, namely, the instant after the mandril stem has been broken;

Fig. 5 is a view similar to Fig; 4 but showing the next stage of operation, namely, ejection of the broken mandril;

Fig. 6 is a section taken along the line VIVI of Fig. 3, the mandril being omitted; and

Fig. '1 is a view in perspective of one of the mandril gripping jaws (in initial position) and elements associated therewith for restraining it in inoperative position.

The main body of the tool is comprised of a slender barrel Ii} that is provided with a longitudinally extending kerf of gradually increasing depth for accommodating a pair of toggle arms l2, I5 (Figs. 1 and 2). mounted on a pin I6 which is received by a boss IS on a rearward part of the barrel Ill. Theknee of the toggle is pivotally connected by a V The toggle arm [4 is I barrel Ill. The purpose of the lever 22 is to afford means for manually applying force via the aforesaid main body so as to operate the tool as will be subsequently described.

The barrel l0, solid rearwardly of the boss I8, becomes tubular as its kerf extends forwardly to receive an .end of the-toggle arm l2 (Figs. 3 and 4). This. tubular portion of the barrel is provided with a slidable crosshead 28 and, for a purpose hereinafter explained, with a compression spring 3!! bearing thereon. The crosshead 2B is connected to that end of the'toggle'arm 12:

by a pivot pin 32. A cross pin 34 projects through opposing slots 36 extending longitudinally; of the barrel It and also projects through-corresponding. holes in the crosshead 28 and an external sleeve 38 into which it is screwed. Thissleeve 3 8 and a hollow but rigid member 40' are threaded together endwise to comprise an anvil portion-42-0fthe tool. A collar 44 is driven into the threaded end of the member to brace it radially. The otherend ofithe. member 40 hasaflat external anviLface 46: for bracing the rivet against retraction of the mandril head and an internal face 48. which will be referred to hereinafter. From the construction just described it will be appreciated thatthe main body or barrel I6 is telescopically related: to the anvil portion 42 of the tool.

The main body of the -.tool is-also comprised of an extension member SUfirmly anchored by. a pin 52. to the barrel It. It is this extension portion 60 of the main tool body which has the mandril gripping mechanism arranged as a self-containecl unit within it and is in telescopic engagement with the member 49.. One. end of the member 50 is engaged by the springg30. A substantially central bore 54' (Figs. 3, 4=and.5) in the member 50 is coaxial with an aperture 55in the anvil face 46, the bore 54 andv aperture 56 being.v of diameters freely to receive the shank or'steni of. a nail-like mandril. 58. .Anejection device in. the form of av spring-backed plunger 60vengageable with the mandril stem is seatedin an enlarged inner end'of the. bore 54.

Fig.3 illustrates :the preassembled mandril 58 in its more ductile tubular rivet 62 and ininitial position relative. to the tool. and a structure S.

It may b'enoted that the flangeof the, rivet is braced by theanvil face 46while amandrilhead 64 (which has been. thrust with the unset rivet through a hole in thestructure Sfrom the accessible tool-lside thereof) is adjacent to.the headless endiofthe rivet barrel. A constriction 66 is normally arrangedin the. mandril stem just below the head 64.

The self-contained mechanism by which the mandril '8'is'first gripped'and thereafter pulled rearward to set the rivet 62 as seen in Fig. 4 comprises a pair ofindependently movable jaws 68 and supported in the member 50 and arranged to have their respective mandril gripping, surfaces 12, 14 extending in the bore 54. The surfaces 12, 14 are generally flat and provided with serrations extending transversely of shallow but straight grooves. formed therein. Together the jaws 68,.

10 are thus adapted to receive. and. clamp. the

mandrilstem'; The jaw. 681is guidably-mountedv in a' k'eyway 16' formed to maintain thegroove in'the surface 12 in parallelrelation to. theaxes of'the mandril and .the' bore 54. The jaw 10, on the other hand, has a socket (Bfor receiving. one end of a toggle element in the form of a ball.- endedflat link 80, the other end of the link 80 beingnested in a socket 82'formed. in a yoke por- 4 tion 84 integral with the member 56 and having a shoulder 85 (Fig. 3).

It should be noted that the link 80 and its pivot sockets l8 and 82 lie in a general plane disposed at an angle to the axis of the mandril 58, which plane intersects the gripping surface 14 about midway of its length. It will further be seen that this pivotal suspension of. the jaw 16'. enables it to be swung longitudinally of the tool and transversely of the bore 54 for cooperative mandril gripping relation to the jaw 68. For a purpose hereinafter explained, a pin-like projecting portion 86" of "thejaw 76 extends freely through a borein theforward. end of the member 50 and normally, i.ae.,..when the tool is in initial operatingposition, is 'enga'geable endwise with the face 48. Bearingon a rearward part of the jaw 10 is a small'compression spring 88 mounted in the yoke84 yieldingly to urge the rearward part of the jaw 10 toward the jaw 68.

Mandril releasing mechanism, also associated withthe jaw 16, comprises (Figs. 6 and '7) a rack Sdpivoted. on a fulcrum pin 92 secured in a boss on the member 46, a triangular pawl 94 mounted on the link Sllfor cooperating with the rack 93, and a compression spring 96 inserted in a bore of themember 4ii for yieldingly urging said rack into position for engagement with the pawl 94. The spring 96 bears on one side. of a step 98 of the rack and the other side of the step 98 is engageable with a stop screw we threaded into the member 49. The'stop screw Hit provides a convenient means for adjusting an inclined cam face ltZlFig. 7) of the-rack heightwise relatively to the pawl 94 and thereby compensatesfor positioned as seen in Fig; 1; Accordingly, the pro- I jecting portion 86 of the jaw 16 may then engage the face 48900 prevent: the spring ,88 from'giving' to the link-Bean initial positionso near-to. dead center as: to. make-difiicult the v initial spreading movement of .jawv 10 :by the. stem .58.- insertion of the mandril between the jaws 68. and lilcauses it-toiengage and :load1the springebacked plungerfifi (Fig. 3) for:subsequentejection action as will be. seen. The spring 88. is then yieldingly.

urging: a: rearward portion .of the. mandril. grippingesurface l4 toward contact with the. surface 12. The. unset rivet' anditsmandril are. thereby retainedinready position in the tool so.'that;op.-'

eration may. be commenced whenever convenient,

and even though-the tool is to be manipulated or: operatedwith its anvilportion 42 directedxdownwardly.

For. the sakeof-clarity and simplicity in clee scribing relative operating movements of thetool elements itwill hereinafter be assumed thatthe.

anvil .portion 42 remains stationary.

Having. placed the loaded tool withthe riveti 62 and mandril'58 projecting through a structure.- S, as. seen in Fig. 3, toset the rivet asshown in. Fig. 4 the operatormay; withonehandrswingtthe .lever 22 toward the main body. ofthe tooland.

in the direction of the arrow- A: (Fig. 1). Such movementzof the lever. 22 serves to. spread the toggle arms [2- and. I4,, thereby retractingthe main body of the tool; includingthe member 50;

. to.-move it rearwardly ofthe anvil portion 42.

Rearward Thus on analysis,it may be considered that, since the anvil portion 42.1requires the 'cross pin 34 and crosshead 28 to remain stationary, the pivot pin 32 is prevented from moving toward the structure S and thetoggle spreading must result in the force acting through the boss I 8 to urge the main body and member 50 rearwardly.

The first result of such rearward movement of the. member 50 is to increase the relatively light initial mandril gripping pressure'effected by the spring 88 by means of the pivotal movement of the link -80 in its sockets 18 and 82, It may be noted that had the link 80 initially been disposed more nearly perpendicular to the mandril 58 the tool would be less able to accommodate mandrils with different diameters and the bite of the jaw'lfl might not have been adequate. Similarly, had the link 80 initially been disposed in more nearly parallel relation to the mandril 58 some tendency for slippage of the mandril gripping surface 14 might be expected. The arrangement, however, is preferably such that the link 80 is inclined away from said parallel relation more than 45 and acts as one arm of a'toggle mechanism in which the jaw I serves .as the other arm and the socket I0 is the knee. Retraction of the member 50 tends to straighten the toggle arrangement so that the jaw serrations are well embedded in the mandril stem before they start rearward movement as a unit with the member 50. The jaw I0 does not slip on the mandril but instead, as the link 80 is forced by retraction of the member 50 to assume a more nearly per-, pendicularpositionrelatively to the mandril, the latter is more firmly clamped and gripped between the grooves of the jaw surfaces I2, I4. Continued effective mandril gripping action by these surfaces is attained because tensioning occurs in each instance only when the mandril stem has first been securely gripped and then, when the jaws move longitudinally of the member 50, they are ordinarily retracted in unison. Filling and, in effect, smoothing of the groove serrations with scraped off mandril material is accordingly avoided in the present tool.

The early part of the operating stroke succeeds in drawing the mandril head 64 into the rivet barrel to upset the rivet 02 as seen in Fig. 4. As the lever 22 is thereafter swung further on its fulcra 24, 24 to complete the installation its mechanical advantage increases and, although much greater power is required to strain and break the mandril stem, no great increase in effort is required to be exerted on the lever.

When the rivet 62 has been upset the mandril gripping mechanism is further retracted with the member 50 to strain and then break the mandril at the constriction 66. Normally at the instant of breaking, the lever 22 will not have quite reached its most rearward position but the pawl 94 will be nearing or engaging the cam face I02. After the mandril is broken, its stem may be easily released from the clamping bite of the surfaces 12 and I4, the particular manner and instant of release depending on the adjustment of, and tolerances in, the tool, and possibly the size of the mandril and the rapidity with which the lever 22 is swung. As will be described, the

6* the rearward stroke of the, lever 22 causes the pawl 94 to ride upwardly on the inclined cam face I02 either to cause the toothed surface I4 to be lifted relative to the mandril stem or to cause pivoting of the rack 90 against the spring 96 and the pawl 94 to move beyond the cam face I02 and become engaged with teeth 89 on the rack 90 as the latter is yieldingly urged against the pawl by the spring 96. If mandril release was not effected when the pawl 94 moved rearwardly up the inclined cam face I02 or up the inclined surface of one of the teeth of the rack 90, lever 22 isreturned, preferably rapidly, i. e. moved forwardly or counter to the direction of arrow A. During the initial part of this return stroke, pawl 94 moves across the rear inclined faces of the teeth 89 either to pivot said rack against the pressure of spring 96 without releasing jaw I0, or to cause the pawl 94 to ride up one in Feg. 4) and the jaw I0 may consequently be.

raised suificiently in the bore 54 to obtain mandril release. Should the jaw I0 still grip the mandril stem, its release will be positively effected by continuing the return stroke of the lever 22. Such further forward movement of the lever moves the member 50 forwardly with the link and the jaw I0 until forward movement of the latter is stopped by the pin 86 striking the wall The impact of the pin upon the wall arrests such movement of the jaw I0 relative to the wall 48. Continued forward movement of member 50 effects a clockwise movement of link 80 (as viewed in Fig. 4) above pivot 82 thereby shifting jaw I0 toward yoke 84 against the resistance of the spring 88 to loosen the grip of the surface 14 from the mandril.

Upon operation of the mandril release mechanism in any of the ways indicated the plunger 69 exerts sufficient force on the end of the mandril stem to effect ejection. The tool is then unloaded and ready for'making the next installation. If a rivet barrel 62 of different length is to be upset the member 40 will be threaded in or out of the sleeve 38 suitably to adjust for the extent of endwise rivet collapsing desired.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a riveting tool of the type in which an anvil portion braces a tubular rivet against the upsetting movement of a mandril, a main body arranged for movement relative to said anvil portion, cooperative mandril gripping jaws within said body and individually movable lengthwise thereof, only one of said jaws having a pivotal connection with the body by which to swing into and out of mandril gripping relation, and means for retracting the body from said anvil portion, said retracting means being effective through said pivotal connection to cause said one jaw to cooperate in gripping and tensioning the mandril.

2. A manually operable tool for installing a tubular rivet by means of an upsetting mandril comprising an anvil portion for bracing the rivet against retraction of said mandril, a main body arranged for movement toward and from said anvil portion and having a bore substantially coaxial therewith for receiving the stem of said mandril, means for retracting the main body from the anvil portion, cooperative jaws arranged and individually supported within the main body fongripping andtretracting: thermandril stem in:

saidzhore; and a slink ipivotally connecting one. of

saidxja'ws sto :thebody ffOri effecting. movement? of said one jaw alongssaidbore-and into gripping relationwith another of saidijaws duringopera-tion ofisaidmeans'.

3. Ina: riveting tool of: the type inwliich an anvil 5 portion: braces a: tubular: rivet against the lengthwiseeof." saidlbore for gripping the stem therein, aiapivotal. element'intermediate the body and one of 'SaidI j awsfor controlling the mandril' grippingrelation of the latter, and meansforrretracting the: mains b'o dy from said" anvil portion wherebythe pivotal-element is actuated to close said jaw by toggle action therewith.

4..A*. manually: operable tool forinstalling a tubular rivetibyameans of. an upsetting mandril comprising: an. anvil :portion adapted for. engage:- ment" with an end of the rivet, a. main body arranged for: telescopic movementwithrespect to said. anvil portion, meansmounted onithe body for. moving: the latter; relatively to the anvil portion; a pair'of mandril gripping'jaws supported insaid. body for cooperative movement longitudinallys thereof; means pivotally mounted in the body for. swinging .one of said jaws into mandrili gripping relation when' the body is retracted from the anvil" portion to tension the mandril stem, and: mechanism thereafter cooperative with said. pivotal: means tozrestrain one of said jaws in anz inoperative: position whereby said mandril stem' is released for ejection.

5. Aaiiveting tool comprising an anvil'portion.

for bracing a tubular rivet against the upsetting movementoffa mandril, a main body arranged for movement relative to said anvil portion, mandril; gripping: mechanism entirely" within said' body and; including; a: pair: off cooperative jaws, one of:- said: jaws :being :movable: in; a lineanpath longitudinally of :ithertool only and .the otherv bee ingr. pivotally connected to: a. member bearing... angularly ontthecbo'dy, vsaidiotherij aw 'being: thus; constrained for movementitowardthe: anvil= por; tionin a" curvezconvergingrwith said path; and

means for retracting said: body from:- said: anvil 2 portion, said. body: and: member constituting: a.

toggle for: effecting convergenceiof said j awsz 6. A tool for-installing:tubularrrivets comprise ing' an anvil portion. for: bracing. at. rivet against.

retraction of ans upsetting.- mandril; a; body retractable from: said anvil 1 portion; means: for i so.

moving the body; mechanismwithin. theibod'y operable by retraction thereofto gripzthenterhof.v

the *mandril; said: gripping mechanismi including": a pair of cooperating jaws inormally individually; movable in paths extending.'longitudinallyof? the 1 tool; and a pivotal. member actuated; by said means and disposediangularly betweensaid bodyand .one of? said i j aws: forv restraining the i move? ment of said one jaw; to a .curve converging withv I thepath'of the other:

SYLVESTER L. GOOKIN.

REFERENCES" CITED The following; references are of record in the V file of. this patent:

UNITED s STATES" PATENTS".

Number Name Date 1,829,696- Wylie- Oct; 27; 1931 I 2,428,165 Ketchum Sept. 30, 1947' 2;438;201' Buchet Mar. 23 1948 2,447,589 Mell'erio Aug: 24; 1948 FOREIGN PATENTS.

. Number: Country Date 564329: Great Britain .Oct; 19; 1944 

